Set the $prefix variable to the default prefix path if none was specified (with --prefix).
PR: 42658


git-svn-id: https://svn.apache.org/repos/asf/apr/apr-iconv/trunk@555794 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/configure.in b/configure.in
index b0cd066..b49dfd0 100644
--- a/configure.in
+++ b/configure.in
@@ -28,6 +28,9 @@
   USE_VPATH=1
 fi
 
+dnl Default prefix path if none was specified
+test "x$prefix" = xNONE && prefix=$ac_default_prefix
+
 dnl check for APR
 API_FIND_APR